There is currently no mode of human disseminated gonococcal infection (arthritis, tenosynovitis, skin lesions) in an experimental animal. This is a problem because the tropism of Neisseria gonorrhoeae for synovial tissues is poorly understood, and the pathophysioloy of joint infection wit the gonococcus has received only limited investigation. The prupose fo this project is to produce hematogenou gonococcal infection in experimental animals through the agency of a trans-aortic valve catheter, with resultant endocarditis. The factos of both host and gonococcus which augment virulence in this setting will be manipulated (gonococcal colony type, auxotype, serum sensitivity; host iron stores, complement levels, etc) such that infection is produced with the hightest possible frequency. The influence of these manipulations upon the occurrence of joint involvement will be evaluated. Once gonococcal arthritis can be produced with predictable regularity, studies of the bactericidal capacity of joint fluid and of phagocytic cells in the mileau of synovial fluid will be carried out. In addtion, the pathophysiology of joint disease will be evaluated by immunopathologic techniques.